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Noun: cesium  see-zee-um
Usage: N. Amer (elsewhere: caesium)
  1. A soft silver-white ductile metallic element (liquid at normal temperatures); the most electropositive and alkaline metal
    - caesium [Brit, Cdn], Cs, atomic number 55

Derived forms: cesiums

Type of: metal, metallic element

Part of: pollucite

Encyclopedia: Cesium